In the construction of semiconductor assemblies, it has been found that curable elastomeric materials can be used to create a space between the semiconductor and its support, such construction being disclosed in the U.S. Patents of the prior art discussed infra. The most common is the assembly of one or more semiconductor chips on a substrate such as polyimide film which forms part of a chip carrier package including a circuit panel or chip housing.
A chip carrier includes a dielectric layer with an array of terminals and may also contain leads. The chip carrier is fastened to a semiconductor chip through the leads or wire bonds. An elastomeric material is disposed between the chip and the flexible dielectric layer of the chip carrier. The chip carrier and elastomeric material are also referred to as an “interposer” or “interposer layer”, by those skilled in the art. The leads or wire bonds of the chip carrier are bonded to the chip so that the terminals of the carrier are electrically connected to the contacts on the chip. The entire structure can then be mounted to a substrate such as a circuit panel or chip housing. The terminals of the chip carrier are electrically connected to contacts on the substrate. The elastomeric layer provides resiliency to the individual terminals allowing each terminal to move as necessary to accommodate tolerances during testing and in the final assembly itself.